Studies on the Transport of Carbohydrates in the Cotton Plant III. The Polar Distribution of Sugar in the Foliage Leaf

Phillis, E.; Mason, Tony

doi:10.1093/oxfordjournals.aob.a090405

Cited by 53 publications

(12 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar gradients in osmotic potential in the phloem have been observed by other workers (9,16,20), although Phillis and Mason (15) found lower sugar concentrations in sap expressed from leaf mesophyll cells than in sap from petiolar phloem. The gradient in osmotic potential was most pronotunced from leaves to phloem and less pronounced from upper to lower phloem.…”

supporting

confidence: 87%

“…The steeper gradient observed in the upper part of the trees may resuilt from a higher concentration of salt in the leaves, since ouir measurements yield total osmotic potentials resulting from both sugars and salts. Our leaf samples contained few large veins (see 15). A large difference in turgor pressuire was observed between the leaves and the phloem, but a tuirgor pressure gradient in the phloem was not observed.…”

mentioning

confidence: 79%

See 1 more Smart Citation

Phloem Water Relations and Translocation

Kaufmann

Kramer

1967

Plant Physiol.

View full text Add to dashboard Cite

supporting

confidence: 87%

mentioning

confidence: 79%

Phloem Water Relations and Translocation

Kaufmann

Kramer

1967

Plant Physiol.

View full text Add to dashboard Cite

“…The starch was digested with a salivary extract under toluene, alcohol extracted, the soluble products of hydrolysis inverted, the sugar determined by the MUNSON-WALKER method, and the result calculated in terms of glucose (2,3,23,42).…”

Section: Plant Physiologymentioning

confidence: 99%

“…alcohol was carried out on an electric water bath with reflux conideniser.5 The accumulated alcohol extracts were evaporated to dryness, the residue dissolved in water and made up to standard volume. On aliquot parts of this solution the total nitrogenl (alcohol soluble N) was determiined by micro-Kjeldahl methods (24) and, after clearing6 with neutral lead acetate, deleading with oxalic acid (17), and acid (3 per cent.HCl) iniversion, the total sugar was determined by the MUNSON-WALKER gravimetric method (6).(3) The residue from alcohol extraction was dried, weighed, and used for the determinatioin of alcohol insoluble nitrogen (proteini N) and starch.The starch was digested with a salivary extract under toluene, alcohol extracted, the soluble products of hydrolysis inverted, the sugar determined by the MUNSON-WALKER method, and the result calculated in terms of glucose (2,3,23,42).A full record of the fate of the carbohydrates during the metabolism of potato discs will be given in a subsequent paper. It is necessary only to remark here that discs, cut from dormant tubers and washed in running tap water for 24 hours, commonly have a total sugar content of about 3.0 mg. per gm.…”

mentioning

confidence: 99%

Metabolic Processes of Potato Discs Under Conditions Conducive to Salt Accumulation

Steward

Preston

1940

Plant Physiol.

View full text Add to dashboard Cite

IntroductionModern inivestigations (11, 34) show that vital activity plays an essential part in salt acetmulationi by planits. The ability to accumulate2 demands properties peculiar to cells which are still able to grow and the rate at which these are utilized is causally related to the intensity of aerobic respiration. Salt accumulation is not merely the result of equilibria at membrane surfaces but demands some "dynamic machinery" in cells-to use a happy phrase which received prominence in a recent symposium. A similar concept is implied by the oft repeated assertion that during salt accumulation work is done and energy exchanges are involved. The identification of the "dynamic machinery" and the mechanism by which the energy stored in substances of high energy content is ultimately utilized in salt accumulation is one of the most challenging problems of modern plant physiology.The earlier work, done on Nitella, Elodea, discs cut from storage organs, and roots, focussed attention upon those biochemical processes in the accumulating cells which involve carbohydrates and suggested that these represent an important part of the machinery of accumulation. In a brief review of available evidence (33) it was concluded that the biochemistry of salt absorption represented a virgin field for investigation and this inspired much of the work to be described in this and ensuing papers.The relationship between salt accumulation and metabolism has been most investigated with reference to respiration as measured by carbon dioxide output. The conclusion to be drawn (11,33, 34) is that the relation between salt uptake and respiration is not a simple and direct one; it concerns the aerobic phases of the respiratory process but it is the oxidation which these involve, rather than the production of carbon dioxide per se, which is causally concerned in salt accumulation. The ultimate connection between respiration and salt accumulation must therefore involve some aspect of the oxidative breakdown of sugar-the ultimate source of carbon substrates-other than the mere evolution of the carbon dioxide which is finally produced. The energy thus released must be involved; not only because it supplies the relatively small amount of energy necessary for the actual process of salt uptake, (a process which tends to increase the free 'This is the first of a group of papers on the biochemistry of salt absorption. 2 Especially that most general type of accumulation which involves the simultaneous uptake of anion and cation and which has been termed "primary absorption." Certain absorption processes in which metabolism is not involved are not in question here. PLANT PHYSIOLOGY energy of the system concerned) but also because it maintains the cells at that general level of metabolic activity which is an invariable characteristic of systems capable of a high degree of salt accumulation. Hence the biochemistry of salt accumulation entails an account of the fate of the carbohydrates metabolized during salt accumulation-an account which must ultimat...

show abstract

“…MASON and PHILLIS (58) found that oxygen was necessary for such transport in the cotton plant, and state: "It is suggested that the mechanism activating diffusion consists in some special organization in the cytoplasm, maintained by metabolic energy, whereby the resistance to solute movement is so reduced that materials diffuse in the sieve-tube at rates com-parable with those in a gas." PHILLIs and MASON (66), moreover, have shown that sucrose is transported against a concentration gradient in the leaf of the cotton plant. This recalls the similar transport of auxin against a concentration gradient in the Avena coleoptile, but is different in that the sugar transport is not as polar.…”

Section: Activated Diff-usion As the Mechanismmentioning

confidence: 99%

Electrical Polarity and Auxin Transport

Clark¹

1937

Plant Physiol.

View full text Add to dashboard Cite

Studies on the Transport of Carbohydrates in the Cotton Plant III. The Polar Distribution of Sugar in the Foliage Leaf

Cited by 53 publications

References 0 publications

Phloem Water Relations and Translocation

Phloem Water Relations and Translocation

Metabolic Processes of Potato Discs Under Conditions Conducive to Salt Accumulation

Electrical Polarity and Auxin Transport

Contact Info

Product

Resources

About